After baseline assessments, eligible subjects will receive 8 consecutive days of otelixizumab infusions, each given over a 30 minute period. Prophylaxis for cytokine release syndrome AEs will be given. At Month 6, following a review of any new medical conditions, concomitant medications, lymphocyte count, Epstein Barr Virus (EBV) viral load and other re-dosing eligibility criteria, subjects will be re-treated with the same dosing regimen. Subjects will be followed for 24 months in this study.